• The korean journal of orthodontics
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• v.34 no.3 s.104
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• pp.241-251
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• 2004

Previous studies have focused on the causes of root resorption after orthodontic treatment and treatment methods to reduce this phenomenon, and have been mainly associated with developed, mature roots. As parents become increasingly interested in their children's' dentition, orthodontists are performing fixed orthodontic treatment on patients of less than 10 years and before the completion of the immature root. Thus, the author evaluated the changes of root length and root form of maxillary immature incisors after orthodontic treatment, compared with those of mature teeth, and investigated the correlation according to gender, treatment duration, and displacement of incisors. The sample consisted of an immature root group of twenty-eight persons (between 8 and 10 years old) and a mature root group of thirty-one persons (between 11 and 15 years old). The crown and root length of the maxillary four incisors were measured with a periapical radiograph, changes in root length and crown-root ratio were calculated, and root form was classified according to a scoring system. The results were as follows. 1. The development of immature roots was not affected by orthodontic treatment and mostly showed normal root length and apical form. 2. Root length of immature teeth was sustained or became shorter, partially in long treatment duration or with open bite patients. Even though the teeth reached their normal root length, they demonstrated a blunt form. 3. Most of the mature roots showed mild resorption, and the form of mature roots was more blunt than the developed form of the immature roots (p<0.05). 4. The developed form of the immature roots was statistically related to treatment duration, while the form of the mature roots was significantly related to the displacement of incisors (p<0.05). 5. In contrast, other variables such as gender, classification of malocclusion, changes in overbite, and changes of U1 to SN showed no correlation with the root resorption of both groups.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.1
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• pp.1-10
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• 2007

악관절 잡음과 동통,과두 흡수를 동반한 퇴행성 측두하악장애는 교합 불안정과 개구장애 를 동반하기도 한다. 진단을 위해 CT나 MRI를 이용해 과두 형태 및 디스크 위치를 파악하 는 것이 유용한 접근법이다. 퇴행성 측두하악관절 환자는 CT나 MRI를 이용하여 진단하고, 과두-원판 재위치와 근 기능 개선을 위해 장기간 교합 안정장치 사용이 필요하므로 교정치료 기간에 변형된 교합 안정장치의 병용이 필요하다. 이에 본 연구에서 교합 안정장치를 병용하여 교합 재구성 증례를 CT나 MRI로 고찰해 보고자 한다.

• The korean journal of orthodontics
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• v.28 no.3 s.68
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• pp.479-486
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• 1998

Bimaxillary Protrusion can be treated effectively in growing patients and in adults with conventional orthodontic therapy. However, In the adult patient, combined surgical and orthodontic treatment modalities may offer distinct advantages over such conventional therapy. In those cases complicate by vertical jaw dysplasia, sagittal dysplasia, or transverse skeletal discrepancy in addition to bimaxillary protrusion, the possibilities of obtaining successful results through orthodontic treatment alone greatly diminish. Surgical retraction of both maxillary and mandibular anterior segments with subapical osteotomies and ostectomies in the extraction site may be a good treatment alternative. Treatment time and possible adverse effects of lengthy orthodontic therapy may be reduced and optimum esthetic improvement may be facilitated. On the following cases, patient who had bimaxillary protrusion with Angle class III malocclusion was treated with combined orthodontic - surgical therapy by anterior subapical segmental osteotomies.

• The korean journal of orthodontics
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• v.33 no.5 s.100
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• pp.399-405
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• 2003

Tooth movement facilitated by corticotomy and distraction osteogenesis, new paradigm in orthodontics, was discussed. Intrusive tooth movement of anterior or posterior teeth was thought to be difficult or impossible. In this study, a part of cortical bone, which was a sort of resistance to tooth movement in alveolar bone, was removed. On the other hand, active bone deposition was made possible in the tension side. That was the main concept of tooth movement facilitated by corticotomy and distraction osteogenesis. Teeth moved at such a speedy tate as we could not imagine in conventional tooth movement, which lead to the reduction of total treatment Period. And intrusive movement was Possible without a side effect, lot example, root resorption or the periodontal breakdown. Those were the superior aspects to the conventional orthodontics.

• The korean journal of orthodontics
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• v.40 no.1
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• pp.34-39
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• 2010

Objective: The aim of the present study was to evaluate the changes in tooth mobility following orthodontic treatment and to obtain information regarding the guideline of retainer wear duration during the post-treatment period. Methods: The sample consisted of twenty patients who had been treated with edgewise appliances. The mobility of the maxillary teeth from the central incisor to the first molar was measured bilaterally by way of the $Periotest^{(R)}$, a non-invasive, electronic device that provides an objective measurement of the reaction of the periodontium to a defined impact load. Tooth mobility was monitored at the time of the removal of the orthodontic appliances and subsequently at three-month intervals during the two years following appliance removal. Results: Tooth mobility decreased rapidly for the first six months and then decreased at a slower rate during the next six months; no statistically significant decrease in mobility was observed during the second year following appliance removal. Conclusions: The results of the present study suggest that adequate tooth stabilization is critical during the first six months following appliance removal and that continued wearing of retainers is recommended at least until twelve months after the completion of orthodontic treatment.

• The korean journal of orthodontics
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• v.40 no.1
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• pp.50-60
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• 2010

The purpose of this article was to evaluate the effects of a new upper molar distalization system, the Frog Appliance, on dentofacial structures in a Class II, division 1 patient. An 11-year-old girl was referred to our clinic for orthodontic treatment. She had a mild skeletal Class II malocclusion with Class II molar and canine relationship on both sides. The treatment plan included distalization of the upper first molars bilaterally followed by full fixed appliance therapy. For the upper molar distalization, a new system, the Frog Appliance, was constructed and applied. Lateral cephalometric radiographs were used to evaluate the treatment results. Distalization of the upper first molars was achieved in four months successfully, and Class I molar relationship was obtained. Total treatment time was 16 months. According to the results of the cephalometric evaluation, a nearly bodily distal molar movement with a slight anchorage loss was attained. In conclusion, the Frog Appliance was found to be a simple, ef ective, non-invasive, and compliance-free intraoral distalization appliance for achieving bilateral molar distalization.

• Progress in Medical Physics
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• v.27 no.1
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• pp.46-53
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• 2016

Periodical calibrations of radiation detectors are important for accurate quality assurance of therapeutic linac. The measuring instruments such as ion-chamber, thermometer, barometer, and survey meter should be calibrated periodically. Period of calibration for these instruments is suggested 6 month to one year in Korea and two years in other countries nowadays. Therefore, the determination of reasonable period for calibration is needed. In this study, we plan to utilize the results of these survey; frequent in use, how to use and stability of instruments, to determine the optimized period of calibration for the instruments in the departments of radiation oncology in Korea based on the ILAC-G24. The SurveyMonkey web-based survey tool was used and the objects of survey were 18 department of radiation oncology in university hospitals, and 15 departments were answered. The 64 questionnaires which supposed to be answered in 50 minutes were classified as the information of candidates, the thermometer, the barometer, the surveymeter, and the ion-chamber. The thermometers and the barometers were not under periodical calibration for more than half of candidates. The periods of calibration of surveymeters were 6 month to 1 year. We expect that the calibration period can be determined based on these survey results.

• The korean journal of orthodontics
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• v.41 no.3
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• pp.174-183
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• 2011

Objective: Orthodontically induced root resorption (OIRR) involves partial loss of cementum and dentin of teeth caused by routine orthodontic treatment. It decreases root length and influences the function of affected teeth. In this study, the treatment and patient factors causing apical root resorption in Koreans were determined. The observed factors were extraction, gender, age, displacement of root apex, total treatment period, total teeth length, and shape of the root. Methods: The records of 137 patients treated with full, fixed edgewise appliances were obtained from the Department of Orthodontics, Dankook University Dental Hospital, from November 2007 to December 2008. Periapical radiographs of the maxillary central incisors and cephalometric radiographs of each patient were used to assess apical root resorption and type of tooth movement. Results: The mean amount of resorption was $1.62{\pm}1.58mm$. The amount of resorption in the extraction and non-extraction groups was $2.10{\pm}1.64mm$ and $1.18{\pm}1.39mm$, respectively. The amount of root resorption increased with the total tooth length. Severe root resorption (> 4 mm) was related to abnormal root shape (blunt, pointed, or eroded). Conclusions: The variables significantly related to OIRR were extraction, initial tooth length, and root shape.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2150-2159
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• 2014

This study was designed to investigate the status of orthodontic treatment and facial plastic surgery among 389 patients who visited dental clinics located in Seoul and Gyeonggi Province. After the collection of data, an analysis was carried out using a spss statistical program. The analysis results are as follows. the level of satisfaction with orthodontic treatment from patients with experience of the orthodontic treatment turned out to be high(p<0.01). Women considered 3.01 to 4 million won to be reasonable cost for orthodontic treatment (p<0.05), which is higher cost recognized by men, and patients with experience of orthodontic treatment recognized 19 to 24 months as the proper orthodontic treatment period(p<0.01). In addition, women showed higher figures than men in their awareness on the need for orthodontic treatment checkups(p<0.001), and facial plastic surgery experience (p<0.01). With respect to the part of the face on which they hoped to have plastic surgery, eye plastic surgery was higher in women (p<0.01), and nose surgery turned out to be higher in patients with experience of orthodontic treatment(p<0.05). Meanwhile, women considered the eye as the most important part among other facial areas (p<0.001), and they recognized that dentist should perform plastic surgery on both jaws among facial areas(p<0.01). In conclusion, the dental medical staff should provide consultations and operate treatment systems in consideration of gender differences and needs of dental patients. In the case of orthodontic treatment for the improvement of facial appearance, especially double jaw surgery which is closely related to the oral function, professional dental medical staff needs to perform the operation, considering the special oral environment. In addition, it is determined that provision of relevant medical information and promotion of dental service is required to provide patients with correct knowledge about orthodontic treatment and facial plastic surgery.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.173-182
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• 2019

Vertical facial growth triggers the rotation of mandible to move the chin point to the downward and backward direction, which showed remarkably effective result making the less prominent chin. Recently, the intraoral removable appliance utilizing class III elastic demonstrated the vertical growth trigger mechanism. The treatment change was very fast and wearing was quite easy, compared to extraoral appliances. The purpose of this study was to verify the duration of the treatment on class III malocclusion using intraoral removable appliances, which designed to accelerate vertical facial growth. 56 patients were selected with the complaint of the protruded mandible and class III malocclusion (overjet : -3 - 0 mm, overbite : 0 - 4 mm). Information like; age at start, duration of the treatment events, type of the treatment, overjet, overbite etc. was collected and calculated. The average age of the patients delivering the initial brace was $8.75{\pm}1.10year$. Most of the anterior crossbite was resolved within 6 months. The total treatment period was $21.79{\pm}10.73months$ with the additional procedures like the alignment of anterior teeth and torque control using additional removable and fixed orthodontic appliances. The correlation study showed that patient's cooperation (p = 0.000) and the use of fixed appliance (p = 0.032) were significantly influenced on treatment duration.